Method of and apparatus for opening bags and forming recesses therein



ocus, 1-937. CHW T 2,095,205

METHOD OF AND APPARATUS FOR OPENING BAGS AND FORMING RECESSES THEREIN Filed Aug. 9, 1935 2 Sheets-Sheet 1 I I IQ INVENTOR .DAV/D Sum/or ATTORNEY D. SCHMIDT Oct. 5, 1937.

METHOD OF AND APPARATUS FOR OPENING BAGS AND FORMING RECESSES THEREIN Filed Aug. 9. 1 25 I 2 Sheets-Sheet 2 INVENTOR Dav/0 Sex/mar ATTORNEY 15 against each other.

Patented Oct. 5, 1937 PATENT ()FFlCE METHOD OF AND APPARATUS FOR OPEN- ING BAGS AND FORIVIING RECESSES THEREIN David Schmidt, Cleveland, Ohio, assignor to The Dobeckmun Company, Clcveland,-hio, a corporation of Ohio Application August 9, 1935, Serial No. 35,510

20 Claims.

This invention relates to a method and to apparatus for forming-a recess or thumb hole in one of the superposed plies or sides of an article such as a bag made of paper, or of regenerated cellulose sheeting, or other sheet material. It is advantageous to manufacture bags by a substantially continuous process, as on machines in which the stock or material is formed into a flat tube, and as this tube of stock advances through a machine various cutting, sealing and folding operations transform the tube of stock into a series of bags which issue from the machine with their edges creased and the plies forming the opposite sides of each bag disposed substantially The purpose of the inven-. tion is to form a recess or thumb hole in one side of a bag only, at the mouth, while the bag is in the process of manufacture, and during the bag forming operation.

In these aspects the purposes of this invention are to provide a method of forming a recess or thumb hole in one side of a bag, which method may be performed during a substantially continuous process of'manufacture; and to provide apparatus for practising this method, which apparatus is adapted to receive and to discharge a bag in a substantially flat condition and is otherwise specially adapted to'operate successively on a series of bags which have been otherwise completed or which are advancing through a machine in the process of manufacture.

Other important objects of the invention are to provide an improved method of opening a bag; to provide apparatus for opening a bag and forming a thumb hole therein; and also to provide apparatus of the class referred to, having an improved construction and relative arrangement of parts. The improved process and apparatus are particularly adapted and intended for the manufaoture of bags with thumb holes from a web of regenerated cellulose sheeting.

While the invention is described and shown in detail, it is evident that the principles and mode of operation may be embodied in other forms and may be modified or improved within the scope of the invention.

In the drawings in which the preferred form of the invention is shown:

Fig. 1 is an enlarged vertical sectional view showing the punch at the upper limit of its stroke;

Fig. 2 is a fragmentary sectional view similar to Fig. 1, but showing the punch on the return or downward stroke as it is about to form a thumb hole;

Fig. 3 is a planview of some of the mechanism shown in Fig. 1, but illustrating a bag being held in a position corresponding to that shown in Figs. 1 and 2 by means of stop mechanism;

Fig. 4 is a plan view of a finished bag, a portion of the upper ply or side being broken away to show the thumb hole;

Figs. 5, 6 and 7 are diagrammatic views illustrating the manner in which a bag is opened for the admission of the punch;

Figs. 8, 9 and 10 are plan views and Figs. 8a, 9a and 10a are edge views of the bags shown in Figs. 5, 6 and '7 respectively; and

Fig. 11 is a section on the line ll-ll of Fig. 1, illustrating the cutting edges of the die.

The apparatus illustrated is constructed and arranged to form a part of a bag making machine of a standard type wherein the stock is formed into a substantially fiat tube from which sections of the required length are cut and made into bags by forming a bottom on one end of each section. The operations which form the bottom of each bag are performed at different stations as the stock or the partially formed bags advance along a predetermined path. As shown in the drawings, bags having their bottoms partially formed are delivered successively in a substantially flat or unopened condition to a cooperating punch II and a die l2 (Fig. 1) where each bag is'opened, the die members are operated to form a thumb hole, and the bag closes and is removed.

As shown in Figs. 1 and 3, means for guiding and conveying the bags to and from the dies comprise spaced parallel angle bars l3 and M, the horizontal legs or flanges of these bars providing a supporting surface along which the marginal portions of a bag l6 may slide while the upright legs or flanges of these angles function as guides for the bags. The bags are advanced alo..g these guiding angle bars by means of pairs of opposed conveying tapes Ila, Nb and 3a, lab, which are disposed along the inner edge of each angle bar with the tapes Ila and 18a arranged for frictional engagement with the lower surfaces of the bags, while the tapes Ill: and lb have similar engagement with the upper surfaces.

In order to release each bag, particularly when dealing with narrow bags, so that it may be opened to'receive the punch which forms the and then about a roller 2| downwardly in an inclined direction to a roller 22. The lower tapes Preferably the rollers I9, Hand 22 are spacedso that a bag is never entirely free. Thus, the rollers I9 and 22 are so spaced that before the trailing end of a bag passes beyond the rollers I9, the leading end of this bag is beneath the rollers 22. This assures proper control of the bags.

Preferably the tapes run continuously from left to right as viewed in Fig. 1, and therefore stop mechanism is provided for stopping each bag whenit has arrived at the proper position for forming the thumb-hole. This mechanism comprises fingers 23 and 24 which depend above the horizontal flanges of the angle bars I3 and I4 into the'path of an advancing bag as shown in Figs. 1 and 3. These fingers are mounted for oscillation about a horizontal shaft 26. These fingers are movable about this shaft in a counter clockwise directionfrom the position shown in Fig. 1 to a position in which the depending ends of the fingers do not interfere with bags passing therebeneath.

In order to accommodate bags of different lengths, the rollers I9 and 2|, which cooperate with the tape I'Ib, are rotatably mounted on stub shafts 21 and 28, carried by an arm 29 on a shaft 3| which is rotatably' mounted in a bracket 32 in which the shaft 3| is secured in the desired angular position by means of a set screw 33. This bracket is in the form of a block which is recessed to fit about the angle bar l3 and to be adjustable longitudinally thereof.

Similarly the roller 22, which cooperates with the tape IIb, is rotatably mounted on a stub shaft 35 carried .by an arm 36 on a shaft 31 which is rotatably mounted in a bracket 38, and secured in the desired angular position therein by a-set screw 39. This bracket is also recessed to fit about the angle bar I3 and to be slidable therealong. A set screw 49 is provided for securing the bracket 38 in any desired position;

The punch is part of a piston 4| having a substantially solid heador body, which is provided adjacent its upper end with a recess 42, while its lower end is in the form of a skirt 43 in which a wrist pin 44 is mounted. The upper end of this piston is adapted to reciprocate through a hole 46 in the die I2. Preferably the upper end wall 41 of the recess 42' is a substantially plane surface inclined at a small angle to the horizontal as shown. The edgesformed by the intersection of this surface with the cylindrical side walls of the piston constitute the cutting edges of the punch. a

In order to provide for holding a bag firmly in position on the die I2, the latter has a series of vertical holes 48 passing through it to afford communication with a passage 49. This passage has communication with suitable means, such as a rotary valve (not shown), for periodically evacuating the passage 49 so as to create suction which acts through the holes 48 to hold a bag to the die I2. Preferably the holes 48 are arranged in rows, and strips 52 and 53 are fitted in grooves a relatively short bushing 54, which is mounted' in a block or casting 56. The upper end of this bushing abuts against the under, surface of the die. The skirt portion of the piston travels in a longer bushing 51, also mounted in the block 56. Between the adjacent ends of the bushings the block 56 is cut away to provide a passage 58 for discharging waste material. A passage 62 extends through the upper end of the piston between the surface 41 of recess 42 and an outer side wall of the piston. When the piston is at the end of its downward stroke the outer end of passage 62 communicates with a passage 63 which is supplied with air under pressure.

The piston 4| is reciprocated by any suitable means and is operated in timed relation to the movement of the bags so that, as each bag pauses over the die the piston will rise, separating the mouth of the bag, will enter the bag, and make its return stroke, cutting out the'thumb hole on its downward stroke. A link 98, pivoted at its upper end on the cross-pin 44 and at its lower end on a cross-pin 99, may be actuated by a lever, the ends of which are shown at 98.

When this apparatus is in operation the tapes convey bags in the direction indicated by the arrows, as viewed in Fig. 1. With the parts arranged as shown in Figs. 1 and 2, the machine is set to operate on bags which are delivered bottom end first. As a bag is about to arrive at the position shown in Figs. 1 and 3, the stop mechanism is operated by any suitable .means (not shown) to swing the fingers 23 and 24 downwardly against the angle bars I3 and I4, so that the leading end of the approaching bag is engaged by these fingers at points adjacent the tapes. It will be observed from Fig. 1 that when a bag arrives at this position it is engaged by the upper tapes Nb and |8b only for a short distance at the leading end of the bag, and these tapes therefore slip over the surfaces of the bag.

As a bag is stopped by the fingers 23 and 24, the air is partially removed from the passage 49 to create a suction which acts through the holes 48 to hold the lower 'side of the bag firmly against the surface of the die I2.

The action of the piston on its upward stroke is illustrated diagrammatically in Figs. to7. As the piston moves from the position shown in Fig. 5 to that shown in Fig. 6, both sides of the bag are moved upwardly. As the lower side of the bag is held against the surface of the die by suction acting through the holes 48, this side swings or flexes upwardly only from the edges of the holes 48 and at a relatively short radius. The

, upper side of the bag being free to move, swings upwardly at a relatively long radius.

As illustrated in Figs. Band 9, this upward movement of the end of the bag causes the iongitudinal edges thereof to approach each other, a result which is more apparent in narrower bags. As the piston continues its upward movement to the position shown in Fig. 'Ifit passes over the end edge of the lower side which therefore swings into the recess 42 and returns to a substantially horizontal position across the cutting edges of the die I2.

- It will be observed that the bag has been opened and that the cutting edges, which constitute the punch I I; are disposedwithin the mouth of the bag. As the piston moves downwardly these cutting edges cooperate with the cutting edges of the die to form a thumb hole on the lower side of the bag, as indicated at I29 in the finished bag I2I.

As the piston continues its downward stroke the material removed in forming the thumb hole is carried into the hole 46 in the die l2. It will be clear from Fig. 2 that, as this cut-away or waste material is being carried through the hole or bore 46, the passage 62 in the piston is brought into communication with the passage 63 which, when the passages are in register at the lower end of the stroke, is supplied with, air under pressure which enters the passage 62 and issues therefrom into the recess 42. This blast of air dislodges the waste material from the surface 4! and blows it out through the discharge passage 58. After the thumb hole has been formed, as just described, atmospheric pressure is admitted to the passage 49 to release the lower side of the bag, and the fingers 23 and 24 having been swung upwardly in a counter-clockwise "direction out of the path of the bag, the latter is carried away by the tapes Ila, Ill) and Mia, lBb.

While the description has been quite detailed as to the construction and operation of the cutter, it will be apparent that changes and modifications may be made in specific embodiments of the invention. The invention is not limited to the exact form or details shown.

What is claimed is:

1. The method of cutting a recess in one side of a bag which comprises separating the sides of a bag by flexing the end portion of one side toward the other side at a relatively short radius while allowing the end portion of the other side to flex in the same direction at a relatively long radius, releasing one side of the bag and intro-' ducing a cutting element into the mouth of the bag, and then actuating the cutting element.

2. The method of forming a recess or thumb hole in one side of a bag which comprises separating the sides of the bag by fiexingthe end portion of one side toward the other side at a relatively short radius while allowing the end portion of the other side to flex in the same direction at a relatively long radius, and forming a recess in the end portion of one side of the bag while separated from the other side.-

3. The method of forming a recess or thumb hole in one side of a bag which comprises swinging the end portion of one side toward the other at a short radius while allowing the end portion of the-other side to swing in the same direction at a long radius until the sides are separated by approximately the length ,of the short radius, moving the sides farther apart, allowing the end portion of said one side to return substantially to its normal position, and forming a recess in the end portion of the latter'side while in normal 0 position. i

4. The, method of forming a recess or thumb hole in one side of a bag, which comprises applying a suction to the outer surface of one side of the bagover an area spaced from the free edge thereof, swinging the end portion of said side toward the other side while allowing the end portion of the latter side to swing in the same direction at a longer radius so as to separate the sides, allowing the end portion of said one side to return substantially to its normal position, and forming a recess in one side of the bag while the sides are separated.

5. The method of forming a recess or thumb hole in one side of a bag which comprises supporting one side of the bag on a substantially plane surface with the mouth of the bag in register with a die, applying a suction tothe outer surface of said one side of the bag over an area spaced from the free edge thereof, swinging the end portion of said side toward the other side while allowing the end portion of the latter side to swing at a longer radius so as to s'eparatethe sides, allowing the end portion of said one side to return substantially to its normal position, and forming a die-cut recess in the latter side.

6. The combination of means for conveying bags in a predetermined path, a cooperating punch and die disposed along said path and movable relatively toward and from each other for forming a thumb hole in a bag, means for holding one side of the bag in position relative to the punch and the die, means for causing the punch to enter the bag, and means for effecting relative movement of the punch and the die.

'7. The combination of means for conveying bags in a predetermined path, a cooperating punch and die disposed along said path and movable relatively toward and from each other for forming a thumb hole in a bag, suction means for holding one side of the bag in position relative to the punch and the die, means for causing the punch to enter the bag, and means for efiecting movement of the punch and the die.

8. The combination of spaced pairs of opposed tapes engageable with marginal portions of bags for conveying the latter, a cooperating punch and die disposed along said tapes for forming a thumb hole in a bag, means for separating the tapes to release the marginalportions of a bag adjacent the punch and die, means for holding one side of a bag in position relative to the punch and die, means for causing the punch to enter the bag, and means for effecting movement of the punch and the die toward each other.

9. The combination of a relatively movable punch and diefor forming a thumb hole in a bag. means for holding the bag in position relative to the punch and the die, means for effecting relative reciprocatory movement of the punch and the die transversely of the plane of the bag to cause the punch to move over the free end of one side of the bag and to enter the mouth of the bag during a stroke in one direction and to form the thumb hole during a stroke in the opposite direction. 7

10.' The combination of a relatively fixed and movable punch and die for forming a thumb hole in a bag, suction means for holding the bag in position relative tothe punch and the die, means for effecting relative reciprocatory movement of the punch and the die transversely of the plane of the bag to cause the punch to enter the mouth of the bag during a stroke in one direction and to cut out a thumb hole during the return movement.

11. The combination of a complementary punch and die, 'means for holding one side of a bag against the die with the portion to be cut away extending across the punch, means for effecting relative reciprocatory movement of the punch and the die to cause the punch to enter the mouth'of the bag and to cut away a portion of said one side of the bag on the return stroke.

- 12. The combination of a relatively movable punch and die for cutting away a portion of a bag to form a thumb hole, means for holding'the bag in position over the die, means for effecting relative reciprocatory movement of the punch and the die'transversely of the plane of the bag to cause the punch to move over the end of one side of the bag and to enter the bag during one stroke and during the next stroke to cooperate with the die to cut away a portion of one side of the bag to form the thumb hole, and means for directing a blast of air against the cut awayportion for removing the latter.

13. The combination of a relatively movable punch and die, means for holding a bag in position with its open end over the die, means for eifecting relative reciprocatory movement of the punch and the die transversely of the plane of the bag to cause the punch to move over the end of one side of the bag and enter the bag during one stroke and during the next stroke to .cooperate with the die to cut away a portion of one side of the bag to form the thumb hole, said punch having a recess to receive the edge portion of the bag, and meansfor removing the cut away portion from the recess.

14. The combination of a die having an opening formed with edges adapted to cooperate with a punch, a punch disposed in said opening, said punch comprising a body portion having a recess provided with edges adapted to cooperate with the edges. of said die, said punch having its outer surface approximately flush with the surface of said die, means for holding one side of a bag against said die with the open end of the bag disposed across said opening and across said punch,

means for elevating said punch until the free end of one side of the bag passes into said recess, the punch then returning to its original position and thereby cutting a recess in the edge of the bag.

15. Apparatus of the class described, comprising a die having an opening therein, a punch operable through said opening, said punch having a recess provided with edges adapted to cooperate with edges of said opening,,said punch having a passage leading into said recess between the edges thereof, means for eifecting relative reciprocatory movement of said punch and said die, and means effective while said punch is within said opening for supplying air under pressure to said passage for discharging material removed by said punch.

16. An apparatus for forming a recess in one side of a bag mouth, comprising a die and punch, means for holding a bag with its mouth in registerwlth the die, means for moving the punch and permitting one side of the bag to pass to one side of the punch, while the other side of the bag remains on the opposite side of the punch, and means for then causing cooperation of the die and punch to cut out the recess.

17. An apparatus for forming a thumb hole in one side of a. bag mouth, comprising a die and punch cooperating therewith, means for supporting a bag with its mouth over the die, means for elevating the punch and for holding one side of the bag so the mouth will spread to receive the punch and for returning the punch to its original position. v

18. The method of forming a recess in a collapsible bag which comprises securing one wall of the bag to a surface disposed adjacent the area to be recessed, effecting relative movement between said surface and a cutting element in a path extending through the plane of the collapsed .bag and substantially across the area to be recessed, and utilizing this relative movement lapsible bag which comprises securing one wall of the bag adjacent the area to be recessed, moving acutting element through the plane of the collapsed bag and substantially across the area to be recessed, and utilizing this movement of the cutting element to flex the walls of the bag and to bring the cutting element within the bag without cutting the latter.

20. The method of forming'a recess in a collapsible bag which comprises securing one wall of the bag to a surface disposed adjacent to the location at which the recess is to be formed so that the portion to be recessed projects beyond said surface, directing pressure'against said projecting portion of said one wall to flex it toward the opposite wall and continuing the application of pressure until after flexure of said one wall said pressure is directed against the opposite wall and 'opens the mouth of the bag, and cutting a recess in the bag.

DAVID SCHMIDT. 

